Vacuum pump for liquid fuels



March 5, 1940. R. M. GRAGG VACUUM PUMP FOR LIQUID FUELS Filed May 22, 1939 gwpmvbozl Ralph M. 6111991.

67w. (Divide/100M vifm Moon 24 Y WNM Patented Mar. 5, 1940 UNITE STATES VACUUM PUlVIP FOR LIQUID FUELS Ralph M. Gragg, Portales, N. Men, assignor to K. D. Leftwich, Lubbock County, Tex.

Application May 22,

3 Claims.

The invention relates to pumps for conveying liquid fuels from a supply container to the fuel tanks of tractors, aeroplanes, trucks and other automobiles and machines, through pneumatic displacement by the use of vacuum, having for an object to provide improved means for this purpose adapted to automatically release the filler cap from the filling opening neck of the tank when the'tank is full to admit the outer air between said cap and said neck and stop the fiow of the fuel. Another object is to provide improved means to prevent the spilling and wasting of the fuel in carrying the same from the supply container to the machine, to prevent overfilling of the fuel tank, eliminate danger of fire, save time and the use of filler cans, barrel faucets and other devices used in refueling said tanks.

The invention consists in the novel construction and combinations of parts as hereinafter set forth in the claims.

In the accompanying drawing,

Figure l is a side view of the invention as applied.

Figure 2 is a section on the line 2-2, Figure 3, showing the filler cap and a portion of the fuel tank.

Figure 3 is a detail section on the line 3-3, Figure 2.

Figure 4 is a detail side view, partly in section, of the glass trap.

In the drawing, the numeral i designates the intake manifold of the motor of an automobile, such as a tractor, aeroplane, truck or other machine, 2 is the supply container and 3 is the fuel tank of the machine, having a filling opening provided with the customary surrounding vertical neck l.

The filler cap 5 is provided with a depending marginal flange 6, loosely engaging over the neck 5, said cap having a central reduced upper extension l, provided with an annular inlet passage 3 for the fuel, having pipe connection 9 with said supply container, and a central. suction passage it, concentric with said annular inlet passage and having pipe connection H with the intake manifold I, of the motor of the machine. The filler cap 5 is provided with an annular gasket 13, engaging the rim of the filling opening neck 4, and the suction passage is provided with a depending tubular extension it, having a lower enlarged mouth 25, the bore of the lower portion of tube M being contracted at E5.

A tubular screen It surrounds and is spaced from said tubular extension M and is located between the outer edge of said mouth l5 and 1939, Serial No. 275,081

that of said annular inlet passage, to screen the fuel as it is delivered to said tank.

By varying'the length of the tubular extension M of the suction passage, the filling of the tank with fuel may be stopped at varying levels. The suction tube or extension It has threaded connection It with said suction passage and on removal of said tube, the screen it resting on the outer edge of mouth It is removable also, for cleaning, etc.

The filler cap is provided with a horizontal nipple 8 forming an extension of the inlet passage and with which pipe 9 is engaged, and with a horizontal nipple iii forming an extension of the suction passage andwith which the pipe H is engaged,

In practice the filler cap is automatically released from the filling opening neck when the tank is full to admit the outer air between said cap and said neck and stop the flow of the fuel.

The suction passage If! and its depending extension Hl act as a vent for the air in the tank, said air being replaced by the liquid fuel drawn into the tank through inlet passage 8, said extension l i being of restricted bore admitting of free passage of the air but checking or choking the passage of the liquid fuel as the level thereof rises in the tank, which fuel will continue to be drawn into the-tank until the degree of vacuum in the tank is reduced to approximately balance the outer air pressure, whereupon the filler cap will be released from said neck to admit the outer air as stated, said cap having a loose fit over or upon the filling opening neck and the pipe connections of the cap with the supply container and the source of suction being loose to admit of such release of the cap. These pipe connections both depend from the cap, the pipe connection 9 of the cap with the supply container depending more directly from the cap and being longer and consequently heavier than the other pipe connection and having a loose or free lower end, thereby providing weighted means for tilting the cap upon the rim of the filling opening neck. This tilting is facilitated by the central reduced upper extension 7 of the cap, with the nipple 8 of which said pipe 9 is engaged.

The pipe connection 9 of the cap with the supply container is of larger diameter than the pipe connection II with the source of suction as indicated by the larger of the two nipples 8' and Ill of the cap, thereby adding to its weight and tendency to tilt the cap upon the rim of the filling opening neck.

Due to the specific gravity of some fuels, there is a foaming of the fuel when it is pumped under pressure, and this foam rising above the heavier liquid tends to pass through the suction tube and pipe line and into the manifold of the motor before the liquid rises to the level of the lower end of mouth I 5 of the suction tube to break the vacuum in the tank 3 as aforesaid.

In order to prevent this foam from being drawn into the manifold of the motor, a depending glass trap I1 is interposed in the suction pipe line, as shown, said trap having a top l8 provided with an inlet passage l9 and an outlet passage 20. The inlet passage has a screen 2| and the outlet passage has a depending tubular extension 22, provided with a T-form lower end 23 adapted to retard the flow of the foaming fuel and deflect splashing thereof. A valve 24 is located in the suction pipe line adjacent the inlet passage of said trap.

The top l8 of the trap is provided with a depending bail 25, having a lower vertical screw stem 26 engaged by a threaded nut 21, adapted to adjust a member 28 into engagement with a lower recess of said trap and press the trap upwardly to engage the upper rim thereof with a washer 29 of the top l8. Upon loosening of nut where-upon the trap may be removed and accu- 2:, bail 25 may be swung to one side upon its upper pivotal connection 30 with the top l8, mulated liquid fuel therein emptied therefrom, etc.

I claim:

1. In a pump for conveying liquid fuels from a supply container to fuel tanks, comprising a cap engaging the filling opening neck of said tank and having an inlet passage for the fuel having pipe connection with said container and a suction passage having pipe connection with a source of suction, said cap having a gasket seating upon the rim of said neck to hold the cap down thereto upon suction being established; means for automatically releasing said cap from said filling opening neck when the tank is full to admit the outer air between said cap and said neck and stop the flow of the fuel comprising a depending extension of said suction passage having a restricted bore to admit of free passage of air but choke the passage of the liquid fuel, said cap having a loose fit over said filling opening neck and the pipe connections of the cap with the supply container and the source of suction being loose to admit of the release of the cap from said neck, said cap having a central reduced upper extension wherein is provided said inlet passage of annular form and said suction passage central thereof, said extension having diametrically opposite nipples for said pipe connections, the pipe connection of the cap with the supply container being of larger diameter than the pipe connection with the source of suction and tending to tilt the cap upon said neck.

2. In a pump for conveying liquid fuels from a supply container to fuel tanks, comprising a cap engaging the filling opening neck of said tank and having an inlet passage for the fuel having pipe connection with said container and a suction passage having pipe connection with a source of suction, said cap having a gasket seating upon the rim of said neck to hold the cap down thereto upon suction being established; means for automatically releasing said cap from said filling opening neck when the tank is full to admit the outer air between said cap and said neck and stop the flow of the fuel comprising a depending extension of said suction passage having a lower enlarged mouth and a restricted bore to admit of free passage of air but choke the passage of the liquid fuel, said cap having a loose fit over said filling opening neck and the pipe connections of said cap with the supply container and the source of suction being loose to admit of the release of said cap from said neck, said inlet passage being of annular form and said suction passage being central thereof, and a tubular screen surrounding and spaced from said depending extension and located between the outer edge of said mouth and that of said inlet passage to screen the fuel as it is delivered to the tank.

3. In a pump for conveying liquid fuels from a supply container to fuel tanks, comprising a cap engaging the filling opening neck of said tank and having an inlet passage for the fuel having pipe connection with said container and a suction passage having pipe connection with a source of suction, said cap having a gasket seating upon the rim of said neck to hold the cap down thereto upon suction being established; means for automatically releasing said cap from said neck when the tank is full to admit the outer air between said cap and said neck and stop the flow of the fuel comprising a depending extension of said suction passage having a restricted bore to admit of free passage of the air but choke the passage of the liquid fuel, said cap having a loose fit over said neck and the pipe connections of the cap with the supply container and the source of suction being loose to admit of the release of said cap from said neck, and a depending chambered trap interposed in the suction pipe to trap any foaming fuel, said trap having an outlet passage having a depending extension provided with a lower T-form head to retard the flow of the foaming fuel and deflect splashing thereof.

RALPH M. GRAGG. 

